Endoscopes are used for a variety of purposes. In general, endoscopes are used to view confined spaces, which are often both dark and dirty. A typical use is in the medical field, where endoscopes are used by doctors to view body cavities in both diagnostic and surgical procedures. Endoscopes are used in many other fields as well. For example, plumbers use endoscopes to inspect pipes, mechanics to inspect engines, and architects to visualize and walk-through scale models of proposed buildings.
The components of a typical endoscope 100 are shown in FIG. 1. Endoscope 100 consists of a rigid or flexible tube 110, having an imaging lens 120 at one end, a grip 130 connected to an eyepiece 140 at the other end, and an optical channel (not shown) that optically couples the imaging lens 120 to the eyepiece 140. The grip 130 can include one or more openings 132, through which various instruments can be inserted and carried to the end of tube 110. For example, various medical instruments such as forceps and scalpels can be passed to the end of tube 110 through openings 132. One or more controls 134-138 can be mounted on grip 130 to control the operation of endoscope 100 or instruments attached to endoscope 100. Endoscope 100 can also include an additional optical channel provided through a second rigid or flexible tube 160 to connect the imaging lens 120 to a charge coupled device (CCD) 164. The CCD 164 can be connected to a display or monitor 166 to provide a digital display of the space observed through imaging lens 120. The optical channel through either the tubes 110 or 160 can be a relay lens system (for rigid tubes) or a fiber optic cable (for flexible tubes), neither of which are shown. Typically, endoscope 100 also includes a light delivery system to illuminate the space observed. For example, endoscope 100 can include an LED (not shown) attached to the end of tube 110, or an additional fiber optic cable through tubes 110 and 160 that carries light from a lamp 162 to the end of tube 110.
As mentioned above, a typical use of endoscope 100 is to view a confined space or an object within a confined space that is both dark and dirty. Thus, when in use, it is often necessary to periodically remove endoscope 100 from the space being observed to clean imaging lens 120. This need to periodically clean imaging lens 120 adds an additional element of complexity to whatever procedure is being performed with endoscope 100. For example, when endoscope 100 is used to perform a surgical procedure, any tissue that is being held by forceps attached to endoscope 100 must be released before endoscope 100 can be removed and imaging lens 120 cleaned. Moreover, when endoscope 100 is reinserted into the cavity from which it was removed, additional material may be deposited on imaging lens 120, thus decreasing visibility of the space being observed and requiring an additional removal of endoscope 100 so that imaging lens 120 can be cleaned again.